title: Diagnostic odyssey of patients with myotonic dystrophy.
abstract: The onset and symptoms of the myotonic dystrophies are diverse, complicating their diagnoses and limiting a comprehensive approach to their clinical care. This report analyzes the diagnostic delay (time from onset of first symptom to diagnosis) in a large sample of myotonic dystrophy (DM) patients enrolled in the US National Registry [679 DM type 1 (DM1) and 135 DM type 2 (DM2) patients]. Age of onset averaged 34.0 ± 14.1 years in DM2 patients compared to 26.1 ± 13.2 years in DM1 (p < 0.0001). The most common initial symptom in DM2 patients was leg weakness (32.6 %) compared to grip myotonia in DM1 (38.3 %). Pain was reported as the first symptom in 11.1 % of DM2 and 3.0 % of DM1 patients (p < 0.0001). Reaching the correct diagnosis in DM2 took 14 years on average (double the time compared to DM1) and a significantly higher percentage of patients underwent extended workup including electromyography, muscle biopsies, and finally genetic testing. DM patients who were index cases experienced similar diagnostic delays to non-index cases of DM. Further evaluation of how to shorten these diagnostic delays and limit their impact on burdens of disease, family planning, and symptom management is needed.
authors.affiliation: Department of Neurology, University of Rochester Medical Center, 601 Elmwood Ave, Box 673, Rochester, NY, 14642, USA, james_hilbert@urmc.rochester.edu.
authors.forename: James E
authors.initials: JE
authors.lastname: Hilbert
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ashizawa
authors.forename: John W
authors.initials: JW
authors.lastname: Day
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Luebbe
authors.forename: William B
authors.initials: WB
authors.lastname: Martens
authors.forename: Michael P
authors.initials: MP
authors.lastname: McDermott
authors.forename: Rabi
authors.initials: R
authors.lastname: Tawil
authors.forename: Charles A
authors.initials: CA
authors.lastname: Thornton
authors.forename: Richard T
authors.initials: RT
authors.lastname: Moxley
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D057210:Delayed Diagnosis; D004576:Electromyography; D005260:Female; D005820:Genetic Testing; D006801:Humans; D008297:Male; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000145:classification / Q000175:diagnosis* / Q000235:genetics*; D012042:Registries; D013997:Time Factors; D055815:Young Adult